Power consumption is a key consideration in devices that are battery powered. A design criterion for a battery powered device is to minimize power consumption to extend the period of time between battery recharges or replacement as much as possible. In some deployments, such as remotely located sensors, battery replacement may be both impractical as well as expensive. Even in situations where the battery powered device is readily available and recharging is easy, such as in cellular telephones, tablets, laptop computers, wearable devices (WDs), and so on, recharging the battery is still an inconvenient and time consuming task.
Radio communications modules (RCMs), which provide wireless connectivity that is so vital to the operation of these battery powered devices, is also a significant source of power consumption. In general, the more complex the communications and/or greater range supported by the RCM, the greater the power consumption. A reduction in power consumption is realizable by putting one or more RCMs of a battery powered device into sleep (or power off) mode when there is no need of data communications while maintaining a simple, low-power wake-up receiver to receive a wake-up packet. The wake-up packet is transmitted by another device to wake up at least one of the one or more RCMs of the battery powered device in order to resume data communications with the battery powered device. The Institute of Electrical and Electronics Engineers (IEEE) 802.11 Working Group has initiated a standard amendment project referred to as the 802.11ba Amendment to standardize such wake-up technique to be added to the 802.11 family of standards.
However, in a communications system (such as an 802.11-compliant communications system) utilizing contention based mechanisms for accessing a shared communications medium, collisions between transmissions simultaneously attempted by different communications devices in the communications system may occur. In some cases, a collision probability as high as 10% may be targeted in order to improve the communications medium utilization, because targeting a smaller collision probability requires the competing devices to choose their random back-off time within a larger contention window. However, increasing the contention window size would decrease the communications medium utilization, because the back-off time chosen by the device wining the contention tends to increase with the contention window size and the communications medium isn't occupied until the back-off time of the wining device expires. Therefore, the collision probability in a contention based communications system typically isn't negligible and there is a need for systems and methods for detecting transmission collisions and for mitigating the impact of the transmission collisions.